Pressure and redox cataract formation and their experimental conditions will be studied in addition to the cold cataract formation in fish lenses. At first it will establish whether there is any species specificity in these cataract formations or one particular fish, let's say tile fish, can be used as a model for all fish lenses in pressure and redox cataracts. A compression chamber with transparent walls will be constructed for light scattering studies under different pressure and temperature conditions. In addition to the light scattering studies any cataract that shows irreversibility will be investigated chemically regarding changes in macromolecular confirmations. These investigations will include measurements on SH and S-S groups, rate of carboxymethylation of SH groups and the availability of tyrosine groups toward reagents such as tetranitromethane.